The invention relates to a remote transmission device designed for automation of an electrical power distribution system, notably medium voltage, comprising means of communication by on-line carrier currents using by capacitive coupling the lines of the power system as transmission support for exchange of information and orders between a computerized remote control system and a plurality of breaking devices, notably remote-controlled switches and circuit breakers located along a plurality of elementary sections of the power system to perform a modification in the structure of the power system affected by an incident, by means of opening and closing operations of the breaking devices involved, the power system being interconnected to source substations controlled by the computerized remote control system by means of specific connections.
To replace transmissions by radio or telephone, an on-line carrier current transmission system of this kind is envisageable to improve operation of medium voltage power distribution systems, notably for remote control, automation, examination, remote customer metering, order transmission and remote measuring applications. A modulation used is single-sideband amplitude modulation extending from 40 to 500 kHz.
The modification to the structure of the power distribution system resulting from the opening and closing operations of the circuit breakers or switches following faults or deliberate operator action can however disturb signal transmission with level weakening phenomena in some sections of the power system, which is detrimental to the reliability of the remote transmission system.